Mask assembly



FIG. 1 is a front perspective view of a mask assembly according to afirst embodiment of our design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof;

FIG. 6 is a left side view thereof, with the right side view being amirror image thereof;

FIG. 7 is a rear perspective view thereof;

FIG. 8 is a front perspective view of a mask assembly according to asecond embodiment of our design;

FIG. 9 is a front view thereof;

FIG. 10 is a rear thereof;

FIG. 11 is a top view thereof;

FIG. 12 is a bottom view thereof;

FIG. 13 is a left side view thereof, with the right side view being amirror image thereof; and,

FIG. 14 is a rear perspective view thereof.

Where included, the use of stippling (e.g., for the cushion) indicates acontrast in appearance with the adjacent line-shaded portion of the maskassembly, e.g., the frame, shroud, elbow, cushion clips, etc.

CLAIM The ornamental design for a mask assembly, as shown and described.